In the question given below, there are 2 statements marked as Assertion (A) and Reason (R). Choose the correct alternative from the following options.

Assertion (A)- Men are disposed , as a rule, and on average, to increase their consumption as their income increases, but not as much as the increase in their income.

Reason (R)- Marginal propensity to consume is the ratio between the change in consumption to change in income.

Both (A) and (R) are true but (R) is not the correct explanation of (A).

According to Keynes, men are disposed , as a rule, and on average, to increase their consumption as their income increases, but not as much as the increase in their income. It means that with an increase in the level of income, consumption rises but by less than the increase in income. 

The marginal propensity to consume is equal to ΔC / ΔY, where ΔC is the change in consumption, and ΔY is the change in income.